Fan control system and method

Abstract

A fan control system for use in a server system is disclosed. The fan control system includes a first monitoring and protection chip, a second monitoring and protection chip, a switch, a plurality of fans and a complex programmable logic device (CPLD). In a shutdown state of the server system, the switch is switched under control of the CPLD so that the fans are connected to the second monitoring and protection chip, receive standby power therefrom and run at a standby power level. When the server system is switched to a working state, the switch is switched under control of the CPLD so that the fans are connected to the first monitoring and protection chip, receive operating power therefrom and run at a higher working power level. This design can address different heat dissipation needs of various applications.

What is claimed is: 
     
       1. A fan control system for use in a server system, the server system comprising a power supply unit, the fan control system comprising:
 a first monitoring and protection chip electrically connected to the power supply unit and configured to receive an operating power in a working state of the server system; 
 a second monitoring and protection chip electrically connected to the power supply unit and configured to receive a standby power in a shutdown state of the server system; 
 a switch electrically connected to both the first and second monitoring and protection chips; 
 a plurality of fans all electrically connected to the switch; and 
 a complex programmable logic device electrically connected to the first monitoring and protection chip, the second monitoring and protection chip, the switch and the plurality of fans, the complex programmable logic device configured to activate the second monitoring and protection chip in response to detecting that the server system is in the shutdown state and switch the switch so that the plurality of fans are connected to the second monitoring and protection chip, receive the standby power therefrom and run at a standby power level, and to activate the first monitoring and protection chip in response to detecting that the server system has been switched to the working state and switch the switch so that the plurality of fans are connected to the first monitoring and protection chip, receive the operating power therefrom and run at a normal power level that is higher than the standby power level, 
 wherein the complex programmable logic device is directly connected to the plurality of fans. 
 
     
     
       2. The fan control system of  claim 1 , wherein the first monitoring and protection chip is implemented as an ADM1278 chip. 
     
     
       3. The fan control system of  claim 1 , wherein the second monitoring and protection chip is implemented as an MP5023 chip. 
     
     
       4. The fan control system of  claim 1 , wherein the switch comprises at least a metal-oxide-semiconductor field effect transistor. 
     
     
       5. A fan control method, which is carried out by a fan control system for use in a server system, the server system comprising a power supply unit, the fan control system comprising: a first monitoring and protection chip electrically connected to the power supply unit and configured to receive an operating power in a working state of the server system; a second monitoring and protection chip electrically connected to the power supply unit and configured to receive a standby power in a shutdown state of the server system; a switch electrically connected to both the first and second monitoring and protection chips; a plurality of fans all electrically connected to the switch; and a complex programmable logic device electrically connected to the first monitoring and protection chip, the second monitoring and protection chip, the switch and the plurality of fans, wherein the complex programmable logic device is directly connected to the plurality of fans, and the fan control method comprises the steps of:
 a) activating the second monitoring and protection chip by the complex programmable logic device in the shutdown state of the server system; 
 b) receiving the standby power at the second monitoring and protection chip; 
 c) switching the switch under control of the complex programmable logic device so that the plurality of fans are connected to the second monitoring and protection chip, receive the standby power therefrom and run at a standby power level; 
 d) activating the first monitoring and protection chip by the complex programmable logic device when the server system is switched from the shutdown state to the working state; 
 e) receiving the operating power at the first monitoring and protection chip; and 
 f) switching the switch under control of the complex programmable logic device so that the plurality of fans are connected to the first monitoring and protection chip, receive the operating power therefrom and run at a normal power level that is higher than the standby power level. 
 
     
     
       6. The fan control method of  claim 5 , further comprising the step of:
 g) deactivating the first monitoring and protection chip by the complex programmable logic device when the server system is switched from the working state back to the shutdown state and looping back to step a). 
 
     
     
       7. The fan control method of  claim 5 , wherein the first monitoring and protection chip is implemented as an ADM1278 chip. 
     
     
       8. The fan control method of  claim 5 , wherein the second monitoring and protection chip is implemented as an MP5023 chip.